The main benefit to each customer is convenience. Compared to debit cards and cheques, a credit card allows small short-term loans to be quickly made to a customer who need not calculate a balance remaining before every transaction, provided the total charges do not exceed the maximum credit line for the card. Credit cards also provide more fraud protection than debit cards. In the UK for example, the bank is jointly liable with the merchant for purchases of defective products over $100.
Many credit cards offer rewards and benefits packages, such as offering enhanced product warranties at no cost, free loss/damage coverage on new purchases, various insurance protections, for example, rental car insurance, common carrier accident protection, travel medical insurance. Credit cards can also offer reward points which may be redeemed for cash, products, or airline tickets.
Credit card issuers usually waive interest charges if the balance is paid in full each month, but typically will charge full interest on the entire outstanding balance from the date of each purchase if the total balance is not paid.
For example, if a user had a $1,000 transaction and repaid it in full within this grace period, there would be no interest charged. If, however, even $1.00 of the total amount remained unpaid, interest would be charged on the $1,000 from the date of purchase until the payment is received. The precise manner in which interest is charged is usually detailed in a cardholder agreement which may be summarized on the back of the monthly statement.
The general calculation formula most financial institutions use to determine the amount of interest to be charged is APR/100 x ADB/365 x number of days revolved. Take the annual percentage rate (APR) and divide by 100 then multiply to the amount of the average daily balance (ADB) divided by 365 and then take this total and multiply by the total number of days the amount revolved before payment was made on the account. Financial institutions refer to interest charged back to the original time of the transaction and up to the time a payment was made, if not in full, as RRFC or residual retail finance charge. Thus after an amount has revolved and a payment has been made, the user of the card will still receive interest charges on their statement after paying the next statement in full (in fact the statement may only have a charge for interest that collected up until the date the full balance was paid, i.e. when the balance stopped revolving.
Many credit cards can also be used in an ATM to withdraw money against the credit limit extended to the card, but many card issuers charge interest on cash advances before they do so on purchases. The interest on cash advances is commonly charged from the date the withdrawal is made, rather than the monthly billing date. Many card issuers levy a commission for cash withdrawals, even if the ATM belongs to the same bank as the card issuer. Merchants do not offer cashback on credit card transactions because they would pay a percentage commission of the additional cash amount to their bank or merchant services provider, thereby making it uneconomical.
Many credit card companies will also, when applying payments to a card, do so at the end of a billing cycle, and apply those payments to everything before cash advances.
For this reason, many consumers have large cash balances, which have no grace period and incur interest at a rate that is (usually) higher than the purchase rate, and will carry those balance for years, even if they pay off their statement balance each month.